Long Range Load Development

Written by Sierra Bullets Product Development Manager Mark Walker

Since I just put a new barrel on my F-class rifle this spring, I figured it might be a good time to discuss load tuning for long range shooting. Getting the most accuracy out of your rifle is one of the most important aspects of load tuning. For long range shooting in particular, using a load that produces the least amount of vertical variation is vital. There are several steps to the process that I use, so I will go through the basics of each.

When I first get a new barrel installed, I like to determine what the loaded cartridge “jam” length is. I do this by taking an empty case (no powder or primer) that has been neck sized with the proper bushing (I like to shoot for 0.002 smaller than the loaded cartridge neck diameter) and seat a bullet long in it so that the throat of the rifle will move the bullet back into the case when I close the bolt. I close the bolt several times until the bullet stops moving back into the case at which point I use a comparator with my calipers and get a length measurement on the cartridge. This is what I consider to be the “jam length” for this barrel and chamber. I came up with 3.477 as the “jam length” for this particular barrel.

Next, I will fire form some brass using a starting load of powder and bullets seated to “jam” while breaking in the barrel. My barrel break in process is not very technical; it’s mostly just to get the brass formed and the rifle sighted in. I do clean every 5 rounds or so just because I feel like I have to.

Once I have the brass formed, I use them to load for a “ladder “ test to see what powder charge the rifle likes. With a ladder test, you take your starting load and load one round each with a slightly increasing amount of powder until you reach your max load for that cartridge. You then fire each round using the same aiming point to see where the bullets start to form a group. For this barrel and cartridge, I started at 53.3 grains of H4831SC powder and increased the load by 0.3 grains until I reached 55.7 grains. I always seat my bullets to “jam” when doing a ladder test. We will determine the final seating depth in another test later. It’s usually best to shoot this test at a minimum of 200 yards because at closer ranges the bullets will impact too close together making it hard to determine which load works best. I shot this test at 300 yards.

Walker2072 copyAs you can see from the target, the lightest load #1 had the lowest velocity and impacted lowest on the target. Shots #2 and #3 were a little higher and in the same hole. Shots #4 thru #6 were slightly higher yet and all had the same elevation. Shots #7 and #8 were the highest on the target however pressure signs were starting to show. For some reason shot #9 went back into the group and the chronograph didn’t get a reading so I ignored that shot.

When picking a load, I am looking for the most shots at the same vertical location on the target. As you can see that would be shots #4 through #6 so I would pick a powder charge from those shots which would be 54.2 grains to 54.8 grains. As a side note, shots #2 and #3 are only 0.851 lower so I wouldn’t be afraid of using one of those loads either. I settled on 54.5 grains as the load I wanted to use. It’s right in the middle of the group so if the velocity goes up or down slightly, the bullet should still hit in the same place on the target.

Now that we’ve settled on a powder charge, I want to find the seating depth the rifle likes. I usually start at jam length and move the depth in 0.003 until I get to 0.015 deeper than jam.  I load 3 rounds at each depth using the 54.5 grain powder charge and shoot a group with each depth at 150 yards. As you can see from the target, the first two groups are not good at all. Next one looks good and is the smallest group on the target.  The next three are not quite as small but the vertical location on the target is almost the same which indicates a sweet spot which will help keep the vertical stringing to a minimum on target. I went with 3.470 which is right in the middle once again and should give some flexibility with the seating depth.

Walker3074ASo after all of that, my load is 54.5 grains of H4831SC and a cartridge length of 3.470. I plan on loading up enough ammo to shoot five groups of five shots and see exactly how this load works on target as well as what the extreme velocity spreads are over several groups.

I sincerely hope some of this information helps you to get the best accuracy out of your rifle. I do not take credit for coming up with any of this, a whole lot of good shooters use this same method or a variant of it when working up their loads.

For more information about load development, please contact the Sierra Bullets technical support team at 1-800-223-8799 or by email at sierra@sierrabullets.com.

Disclaimer: Load data represented here may not be safe in your rifle.

This entry was posted in Competitive Shooting, Reloading and tagged , , , . Bookmark the permalink.

28 Responses to Long Range Load Development

  1. Davis Bush says:

    Good info. Since we do not as individuals have any access to pressure testing equipment this is a good way to test for consistent pressures. “Vertical string” is generally attributed to seating depth once the powder charge is determined. Done in order to keep a constant as a baseline is a very good indicator. Note over time throat erosion will necessitate a change in seat depth.
    p.s. your barrel is NOT worn out.

    Next article should be on temperature/elevation changes on load performance.

    If people will stop informing others on good load development it would make it easier for me to beat them !!!!


  2. David (Rupe) Ruppel says:

    Mark, Thank you for explaining this so well! I have tried to figure out load developement using the ladder method by reading several write ups, but til now I could never wrap my Gray matter around what they were trying to explain. Your explaination with your targets helped so much that I now understand what I’m looking for and what I should be doing. Thank you for spelling it out for me and please keep load developent articles coming!


  3. John Snell says:

    I’ve been experimenting with OCW and OBT theories, and using QuickLoad to predict and explore load behavior. Your method and results are right in line with my findings. Several shots of different loads hitting near the same elevation is consistent with an Optimum Charge Weight (OCW) load, which often falls near an Optimum Barrel Time (OBT), and since changing seating depth actually changes barrel time slightly, this is a tweak to achieve an OBT node. Besides outstanding groups, I’ve found much lower Extreme Spreads (ES) when a load meets these criteria and in addition I’ve found that such a load will continue to produce small groups for more shots between cleaning than any other load, and does so by a wide margin.

    Thanks for publishing a simple short and accurate method of load development!


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  5. Eric says:

    What is your rifle’s caliber? Which bullet?


  6. John T. Simmons says:

    Dear Mark,
    Thanks for sharing a super process and your results. Frankly, the way that you use jam-length loads to break in a barrel would frighten my reloading friends. They might think that one needs to use shorter cartridges to begin with. I, however, think that it is a brilliant way to work up the load for a new barrel. By starting out with jam length loads and basing your max. load on that C.O.L., then you get a safer, working-load charge weight for the shorter cartridges that you load once you determine the optimum C.O.L..
    I have not yet discovered neck sizing dies that have inter-changeable bushings for different sizes. Please advise. Sincerely, -John Simmons


  7. Eric Christianson says:

    Redding and Forster both make high quality neck sizing bushing dies, Forster will custom polish their full length sizer dies to whatever neck dimensions you specify (for a reasonable fee). Lee makes a collet and mandrel type neck sizing die that minimally works the brass and is not as sensitive to case neck wall thickness as standard or bushing style dies. The Lee dies are very inexpensive. If you wish to increase the neck tension with Lee collet dies, you will need to order additional (smaller dia.) Lee mandrels.


    • John Simmons says:

      Thanks a million Eric!
      I spend so much time working that I rarely have time to read up on the finer points of reloading, so I didn’t realize what you shared about Lee collet and mandrel dies even though I had seen them advertised. Also, I had not heard of the Redding and Forster neck sizers with the bushings. The concept makes sense to me since I do get info from Sierra load manuals and rifle blogs. I have a good micrometer and I use it. Again, thanks and safe and accurate shooting to you. Sincerely, -John Simmons


  8. kenneth kephart says:

    Wonderfully informative!!
    I’m shooting a Stevens 200 in 7mm-08, and a Savage 111 in 7mm Rem Mag. Although both are “hunting” rifles I have been shooting many 3shot groups attempting to find the right powder charge, and COL for both of these rifles.
    Alas I’m using Alliant powder, and bullets weighing anywhere from 120-160 grains.
    The issue with Alliant(even though I like this powder) is the large range from min to max loadings.

    With your help, I’m well on my way to much better accuracy out of both rifles!!




  9. Rob McComb says:


    As a new handloader looking for a solid strategy for load development, I really appreciated reading this article.
    One question I have regarding your standard procedure is how long you wait between shots.
    My last time at the range, I used my phone with a one minute countdown timer, which I forced myself to use between every shot, with the chamber empty and bolt open.
    Do you use a set amount of time, or play it by ear?


    • Rob – For this particular rifle, I did not wait for the barrel to cool between shots or groups. Since F-Class matches usually consist of twenty round strings of fire, load development with a warm barrel is not a bad thing. However, if you are working up a load for a long range hunting rifle and need to determine what works best for cold bore shooting, I would definitely let the barrel cool between shots and groups. – Mark


  10. John says:

    This seems like a useful method for determining in relatively few shots the optimal charge and then seating depth for a given load. If this test is performed with a chronograph, could the average fps of the group that performed best be effectively used as a starting point for bullets with different weights or styles (eg. Sierra MatchKing 168g vs Sierra MatchKing 175g or GameKing?) Are the harmonics the different between weights and styles or does the feet per second control for this variation? Similarly have you found that the rifle “likes” a certain jump regardless of bullet style or does this vary based on the shape, weight etc.?


    • John – Each barrel and chamber will have its own velocity node that works best with the powder and bullet combination that you have selected. The velocity you settle on with one projectile will probably not be optimal for another bullet even if they have similar grain weights. You should always use a safe starting load to begin your load development when changing projectiles. As far as seating depths, that too varies from bullet to bullet and barrel to barrel. Most of the time my seating depth will be no more than 0.015 to 0.020 shorter than my jam length so rarely do any of my bullets truly jump. However some really good shooters will not hesitate to jump their bullets and usually achieve very good success. – Mark


  11. bob Johnson says:

    he’s done an excellent job. but I go one step further and that is I smoke my bullets and then I slam the bolt home. do three times and than I reseat the bullet where its just touching the rifleings of the barrel. reason is to prevent pressure jump during firing. hopes this helps? still reloading after 30 some yrs.


  12. PJ Connolly says:

    Hi Mark,
    Excellent article and I remember speaking to you about you load development techniques at the Creedmoor and Emerald matches this year. My question is do you then experiment with neck tentions or what are your thoughts on this subject.
    Many thanks, PJ Connolly.


  13. Chuck McDonald says:

    Hi Mark,
    Sorry I am so late to this article. For years I have always just used the recommended COAL and varied the charge and hoped for the best results when developing a load. I would like to use a true method such as this as a tool for load development. Unfortunately the facilities I have access to is limited to 100 yards. Is it even worth trying to do this at such a short distant. In reading your article, I am thinking it is not a method I can employ.

    Best Regards,
    Chuck McDonald


  14. Tom Roberts says:

    I have been reading about using the ladder test to develop loads and one thing I see that concerns me is they recommend loading 20 rounds for the test, starting with max load and decreasing charge weight. This will put the lighter loads below recommended min. powder charge. Is this something to be concerned with, should one use the range between min and max loads even if 20 rounds are not used.


    • Tom – I would definitely stay between the minimum and maximum loads listed to be safe. If you wish to use 20 rounds for the ladder test, just use a smaller weight increment between rounds to make sure it doesn’t fall below the minimum recommended load. – Mark


  15. Scott Cureton says:

    Great article. Creating an actuate rifle is awesome when everything lines up. I still grin at the 4 shots in same hole with 308 factory rifle @200 and wince at the ones that defy common sense. So many factors involved. Theoretically , if every round were built identical they would shoot in the same hole with any rifle but, the rifle changes with the environment and fouling too. Achieving perfect rounds and a consistent rifle is one heck of a task. Using harmonic nodes like this article talks about is a must unless your barrel is so thick that it doesn’t vibrate much. Big fan of fat short barrels when it comes to reliable precision but, finding that sweet spot on lightweight sporter is priceless.


  16. Bruce Goodman says:

    This has been very helpful information, as I am new to both long range accuracy shooting and load development. I ran this test with powder charges in .5 grain incraments from published min to 0.1 grain over max with no signs of pressure. And again the following day with charges in 0.3 gr incriments above and below the previous “best load”. I was able to get a “best load” group of 1.228″ high by 0.888″ wide at 300 yards with a Savage 114 AC chambered in .270 Win with bullets (135 SMK) loaded at jam length of 2.8230 CBTO. My remaining question is with these results can I really expect much more accuracy from adjusting the seating depth?


    • John Snell says:

      What you have done so far is to adjust the barrel time so that the bullet exits while the barrel is still moving upward in resonance. At this point, faster bullets exit when the barrel is pointing lower, and slower bullets exit with the barrel pointing higher, thus tuning the vertical. When you adjust seating depth you will be changing the barrel time slightly, and seeking uniformity. When you find it, you may decrease your group size significantly. You may also find a seating depth that yields more well rounded groups. Do the seating depth test at 100 yards to keep wind effects to a minimum.


    • Bruce – Seating depth can make big changes. I have always considered the seating to be as important as the powder charge. So certainly experiment and locate the length that improves the groups. – Duane Siercks, Ballistic Technician


      • Bruce Goodman says:

        Thanks Duane. What would you recommend as a max length of jam. Current load is jammed .003 past touching the lands. I am considering running down to .015 short of jam length.


      • Bruce – It is hard to give an answer other than you need to experiment to see what response the rifle gives. Let the rifle tell you what is working best. I rarely start load development with a jammed bullet. Seeing as how you already have, back the bullet up about .005″ and test, back up another .005″ and test again, repeat. – Duane Siercks, Ballistic Technician


      • Bruce Goodman says:

        Will do, thanks for the advice.


      • John Snell says:

        Conducting an Audette test at other than zero jump is less than optimal. Except if magazine length is an issue, then start at max magazine length. Jam length will ensure that load is never over pressure. Not safe to go the other way.


  17. Chris says:

    I am just starting load development for my Ruger RPR in 6.5 CM. I am not new to reloading but have only loaded pistol calibers and 45-70 rifle cartridges. This is my first bottle neck reload development. I see that you load your ladder loads to “jam length”. I guess being new to reloading bottle neck cartridges has me concerned about having the bullet jammed into the rifling as I have always read that this increases pressures. I may be (and probably) am wrong with my concern but wanted to check to make sure I understand what “Jam length” is before I start load development.
    Thanks, and great article.


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